Method of making rollers



April 4 H. J. THIELKER METHOD OF MAKING ROLLERS Filed Dec. 30, 1938 m RKmL mm A 7' TOR/V5 Y Patented Apr. 6, 1943 METHOD OF MAKING ROLLERS HenryJ. Thielker, New York, N. Y., assignor to Western Electric Company,Incorporated, New York, N. Y., a corporation of New York ApplicationDecember 30, 1938, Serial No. 248,451

3 Claims.

This invention relates to a method of making rollers, and moreparticularly to a method of making printers rollers such as are used tocarry ink or other pigment material from one member to another, e. g.the inking rollers used in direct printing or the transfer rollers usedin offset printing or other analogous procedures.

One variety of offset printing, quite extensively practised, appears inthe art of making imitation wood grain finishes, imitation marblefinishes and the like, in which the pattern of the material to beimitated is reproduced by any well known method, e. g. photoengraving,on a master plate, usually of metal, and is thence transferred by theusual methods of offset printing by means of a transfer roller to thesurface to be ornamented. Such transfer rollers ordinarily consist of arigid cylindrical body of wood or metal having its surface provided withan outer layer of relatively soft resilient material. Various substanceshave been used to make this outer layer which must present a smoothprinting surface, must be impervious to and unattacked by the pigmentsand their vehicles used and the solvents which may be used to clean theprinting sur face, and must be resilient. One substance frequently usedfor this general purpose is the familiar printers compound, a mixtureconsisting principally of glue and glycerine in proportions which willvary with the hardness desired and with climatic conditions among otherfactors. In the making of such rollers various procedures have beenadopted, almost invariably including some step of melting and castingthe compound, either directly on the roller core or as a slab to besubsequently attached to the surface of the roller. The importantdesideratum in any such case is to have the layer of the compound on theroller as free from bubbles throughout the mass generally as practicableand particularly to have the working surface free from bubbles, wrinklesor other irregularities.

An object of the present invention is to provide a method of makingprinters rollers faced with printers compound, which method shall besimple, rapid and effective to produce rollers having a smooth, cleanand unflawed surface.

With the above and other objects in view, one embodiment of theinvention may be presented as a method of making printers rollers whichmethod comprises steps of pouring molten printers compound or the likeon a fiat, flexible sheet of smooth impervious material, such as paperfaced with lacquer, chilling the bottom of the poured compound tosolidify the lower part while the upper portion remains tacky, rollingup the slab of compound together with the supporting sheet about aroller core while the upper surface of the slab in contact with the coreis still adhesively sticky and soft, allowing the rolled up and adheredslab to become set throughout, and stripping off the supporting sheet.

Other objects and features of the invention will appear from thefollowing detailed description of embodiments thereof in a method of andmeans for making printers rollers, taken in connection with theaccompanying drawing in which the same reference numerals are applied toidentical parts in the several figures, and in which Fig. 1 is aperspective view of the base member of an apparatus used in carrying onthe method of the invention;

Fig. 2 is a similar view of the base with a supporting sheet and a pairof removable side rails thereon;

Fig. 3 is a view similar to Fig. 2 showing a partially smoothed outcharge of molten compound on the sheet;

Fig. 4 is a similar view showing the side rails removed and a rollercore in position on the partially solidified slab preparatory to rollingup the slab and supporting sheet on the core;

Fig. 5 is a view similar to Fig. 4 showing the rolling up operationpartially completed;

Fig. 6 is a perspective view on a slightly larger scale of a finishedroller with the supporting sheet partly removed; and

Fig. 7 is a similar view of a completed roller.

In the apparatus herein disclosed a base, shown complete in Fig. 1, hasa fiat horizontal table 20 of any suitable material such as wood or anyof the commercially available and suitable plastics, preferablysupported for convenience on legs or cleats 2|. A transverse verticaldam 22, here shown as a piece of angle iron screwed to the top of thetable, extends across the table at one end. A chilling member or plate24 is set into the top of the table to have its smooth upper surfaceflush with the top face of the table. This plate 24 is composed of anysuitable heat abstracting and conducting material such as metal or stoneor glass or the like, a preferable material being stainless iron orstainless steel for obvious rea sons of emciency and convenience.

In Fig. 2, a compound supporting sheet 25 and an overflow sheet 26 havebeen laid down on the base over the chill plate 24 and removable siderails 21 have been put in place on the sheets. The sheets 25 and 26 areconveniently of the same material. A preferred construction for thesesheets comprises a tough, durable, flexible lamina of any suitablematerial faced or formed to have its upper surface smoothly polished.Such a sheet may be made by providing a sheet of thin, tough paper ortextile with a top facing of some bright finish lacquer, such as one ofthe cellulose acetate or pyroxylin lacquers, or a suit able varnish,enamel or the like. Or the paper may be covered with a thin metal foil.Or the sheet may be a tough metal foil without any backing or a flexiblesheet of a suitable artificial resin or plastic. stance or substancesused may be any which will yield a durable, tough, impervious sheethaving a polished smooth upper surface, and sufficiently flexible to bewrapped together with a slab of partially solidified compound about aroller core as hereinafter described.

The side rails 21 are preferably formed, as shown, with upstanding innerWalls or faces 28, and with notches 29 to receive the vertical flange ofthe dam 22, and are provided with clamping means 30 ali'both ends tohold them rigidly and removably in place on the table 26. The clamps 30at the far' ends of Figs. 2 and 3 and only partiallyshown'are'preferably like those shown complete at the near ends. Each side rail ispreferably shod along its under surfac with a shoe 3! which; projectsinwardly as shown to provide at each edge of the space between therails, a vertical limit wall 32 and a horizontal supporting or gaugingsurface 33. The shoes 3| may conveniently be made removable from therails proper if desired for interchange for other rails of other Widthsof the surfaces 32 and 33; or the shoe may be integral with the railproper.

' The sheet is placed on the plate 2 with the near end of the sheet'abutted against or even turned up against the further face of the dam22.

The subg The sheet 25 is laid with its near edge matching the terminalfar edge of the sheet 25, and the twosheets are preferably locked inthese positions by the pressure of the side rails and their clamps.Therails are so positioned that the opposed faces 32 or therail shoesare spaced'apart a distance equal'to the axial length ofthe rollersurface to be made and the distance from the dam 22 to the far end ofthesheet 25 is equal to the peripheral length of the roller surface tobe made.

The distance between the rail shoes may be any desirdamount' up to thewidth of the plate 24, and the distance from the dam 22 to the far endof the sheet 25 may be any desired amount not extending beyond the farend of the plate 24.

When the apparatus has been thus prepared, a quantity of molten printerscompound, as gauged by the skill and experience of the operator or aspre me'a'sured and prescribed, is poured on the sheet 25. By means of ascraper or doctor 34 of suitable length to extend between the side railsand rest on the two surfaces 33 and having a straight bottom edge, themolten compound is spread to form 'a slab bounded at the near end by thedam 22 and at the sides by'the vertical faces 32. A slight excess ofcompound is usually used andthis is allowed to spread out over theoverflow sheet. The thickness of the slab thus formed is evidently equalto the vertical width of the surfaces 32.

The under side of the slab 35 of compound thus formed being separatedfrom the cold, heatabstracting 'plate'ZA only by the thin sheet 25 israpidlychilled andcongeals and sets to a resilient jelly, while theupper surface cools more slowly. when the 'slab has 'reached'a state inwhich most of its inass'has' set, but its upper surface is stilladhesively soft and tacky, the rails are removed, a knife is run throughthe slab along the line of juncture of the sheets 25 and 26, and thesheet 26 with its small burden of waste compound is removed. A rollercore is then placed in position as shown in Fig. 4.

The roller core, generally indicated at 43, comprises a cylindrical body4| of wood, metal or other suitable material provided with axiallydisposed handles 42 and provided on the outer face of the cylindricalbody with a firmly attached sleeve 43 of resilient material such as softrubber,

although" in some instances this sleeve may be that the dam 22 entersthe notch 44 and the rear face of the notch is applied against the rearface of the dam. The core is then rolled along away from 'theobserver,as in Fig. 5, with more or less pressure downwardly according to thesoftness of the yet unhardened topsurface of the slab 35. The slab beingadhesive on top adheres to and is rolled up on the roller c ore togetherwith the supporting sheet 25 which adheres to the under face of theslab, although lightly because of the polished surface of the sheet.

The completed roller with the sheet 25 adhering to its outer surface maythen be set aside to allow the slab 35, now the surface layer of theroller, to harden and set completely, the roller being preferablysupported meanwhile by its handles 42. When the layer 35 has 'setcompletely, the sheet 25 is stripped off as shown in Fig, 6, and thecompleted roller, as shown in Fig. '7, is then ready for use. If theroller is not to be used at once, the sheet 25 may be leftin plac on ituntil the time for use arrives, and will protect the working surface ofthe layer 35' especially from dust.

The roller core shown here is only one of many forms and constructionswhich such cores may take, but the slight modifications required toadapt the apparatus toother forms will be obvious. Thus if the rollerhas no longitudinal notch, the dam 22 will have only the height of thefaces 32.

Caresh'oul'dbe taken when the sheet 25 is first spread on the-base toavoid any entrapment of air between the sheet and the base. The compoundto be poured may most'conveniently and satisfactorily be melted in somecontainer whose pouring-outlet draws from-near the bottom of thecontainer. The compound may be melted and held in a moltencdndition insuch a container until any air bubbles in-the mass have risen into theupperp'art. Cbmpound'poured from the bottom will then be subs'ta-ntiallyfree from bubbles andwill iyield a satisfactorily homogeneous andunfla'wed slab. g I

The embodiments herein-disclosed are illustrative and maybe-modified anddeparted fromvariously without departing from the spirit and scope ofthe inventionfas pointed out-in and limited solely by the appende'dclaims.

What is'claimedis:

l. The method of making rollers whichmethod comprises'steps of forininga uniformly thick flat layer of molten roller surfacing material,chilling 'one faceonly of the-layer to cause the material to set-asaslab having one solidified face and one adhesively'soft face, rolling'up the slab about a roller core with the' soft 'face of the slabincontact with the core and while thesoft face is still adhesively sticky,and allowing the rolled up and adhered slab to set throughout.

2. The method of making rollers which method comprises steps of pouringmolten roller surfacing material on a flexible impervious sheet, causingthe material to partially set as a slab supported on the sheet, rollingup the slab and sheet together on a roller core to cause the slab toadhere to the core with the sheet outside, causing the slab to setthroughout, and stripping the sheet from the slab adhered to the core.

3. The method of making rollers which method comprises steps of pouringmolten roller surfacing material on a flexible impervious sheet,spreading the molten material into a layer of uniform thickness on thesheet, chilling the sheet to cause the material to partially set as aslab solidified at the bottom thereof and tackily soft on its topsurface and supported on the sheet, rolling up the slab and sheettogether on a roller core to cause the slab to adhere to the core withthe sheet outside, causing the slab to set throughout, and stripping thesheet from the slab adhered to the core.

HENRY J. THIELKER.

